Bone saw



BONE SAW Filed March 29, 1926 I5 Sheets-Sheet 1 1 l L s 5;;

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Sept. 18, 1928. 1,684,815

W. F. WELLS BONE SAW Filed March 29, 1926 3 Sheets-Sheet 2 4/ 5 {4g 5 Wan,

W. F. WELLS Sept. 18, 1928.

BONE SAW 3 Sheets-Sheet 3 Filed March 29, 1926 Patented Sept. 18, 1928.

PATENT OFFICE.

WILLIAM FRANKLIN WELLS, OF CHICAGO, ILLINOIS.

noun saw.

Application filed March 29, 1928. Serial No. 98,168.

This invention relates to improvements in portable power actuated meat cutting machines or bone-saws intended and adapted particularly for use in retail meat markets, and has for its object to provlde a dev1ce of this character which is very efficient, easily and quickly adjusted to position ad acent the block on which the meat is supported and with respect to the angle at which the cut is to be made and also in height and is otherwise constructed and equipped to meet the requirements of a tool of thischaracter.

A suitable embodiment of the invention is illustrated in the accompanying drawings 4 wherein Fig. 1 is a fragmentary top plan view of a bone cutting machine constructed in accordance with the invention.

Fig. 2 is a view partly in elevation and partly in longitudinal section.

Figs. 3 and 1 are vertical sections on the lines 33 and H, respectively, of Fig. 1.

Fig. 5 is a section of the line 55 of Fig. 1.

Fig. 6 is a bottom plan view of the saw carrier of the machine.

Figs. 7 and 8 are, respectively, sections on the lines '?'i' and 8-8 of Fig. 1.

Fig. 9 is a bottom plan view of one end of the saw carrier showing a brake em loyed.

Fig. 19 is a detail section on tile line 10- 1c of Fig. 1.

Figs. 11 and 12 are detail perspective views of a saw tension adjusting device employed.

Fig. 13 is a sectional view of one end of the saw carrier, showing, diagrammatically, a modification of the structure to include a field magnet of a motor and the armature therefor carried by one of the pulleys over which the saw is trained.

The machine includes a suitable base 1 carrying a housing 2 for an electric motor 3 having a vertical shaft. The casing 2 has a central opening at the top bordered by a flange 4 in which the lower end of a. standpipe 5 is telescopically fitted and secured by the set-screw 6. The upper end portion of the pipe 5 telescopically receives the lower end portion of pipe 9 which is provided with the contractible collar having the flanges 7 through which a bolt 8 1s passed, for contracting the collar to engage the pipe 9, the latter having a longitudinal slot 10 in its upper end portion and being rotatable relatively to pipe 5. The motor shaft is connected with the flexible shaft 11 by means of a slidable joint 12 of telescopic form for permitting take-up as the pipe 9 is adjusted vertically relatively to pipe 5. The flexible shaft 11 passes through pipes 5 and 9 and projects through the slot 10.

A cap 13 is rigidly mounted on the top of pipe 9 and carries a sleeve 14, horizontally disposed and provided with a toothedend. The stud v15 of'a shaft 16 passes through said sleeve 14 and carries a toothed collar 17, keyed thereto, for meshing with the toothed end of the sleeve 14, said collar 17 being slidable on said shaft against the action of the spring 18 for releasin it from engagement with the toothed en of the sleeve 14:. The spring 18 is confined between the collar 17 and a washer 19. B reference to Fig. 3 it will be noted that the cap'13 has a stem or shank 20 provided with a longitudinal rib. 21 to fit the slot 10 of pipe 9.

Keyed to the shaft 16 are two collars 22 whlch are disposed between and in contact with the ears or lugs 23 disposed at one end of a frame or casting 24. A air of springs 25 are coiled about shaft 16, one end of each thereof being engaged with a collar 22 and the other ends thereof bearin on the frame or casting 24. for yieldingly supporting the same in the position shown in Fig. 2.

The frame or casting 24 comprises a straight inverted channel shaped middle port1on and two substantially circular end portions 26 and 27, the former bein provided with the ears or lugs 23 and iiemg also provided with an extension portion 28 of arcuate form. Each of said end members 26 and 27 (including the portion 28) is provided with a downwardly projecting annular flange 29 constituting continuations of the flanges of the middle portion 24, said end portions constituting hollow elements to receive the pulleys 30 and 31 over which recess. Fitted in the central opening in'the block is a shaft 38 threaded at the end projecting through said opening and provided between its ends with an annular flange 39 for engaging the bottom face of the block. A cup nut- 40 cooperates with the flange 39 to rigidly secure the shaft 38 to the block 35, the central opening in the bottom of the recess receiving the block 35 being of such shape and size as to permit the aforesaid slight arcuate adjustment of said block, this being for the purpose of adjusting the position of the shaft 38 for reasons hereinafter set forth. Rotatably mounted on the shaft 38 is the pulley 30, suitable anti-friction bearings 41 and 42 being interposed in a well-known manner.

The shaft 38 for the pulley 31 is mounted exactly similarly to the shaft 38 of pulley 30 but the block 35 is, in this instance mounted in a corresponding recess in a member 43 fitted to slide in a slot in and extending diametrically of the top wall of the portion 34, the direction of sliding movement of the member 43 being parallel with a plane common to the axes of both shafts 38. The shaft of the pulley 31 thus is capable of being moved bodily relativelyto the shaft of ulley 30 for adjusting the tension of the hand-saw 32. This is effected by means of the spring 44 bearing upon one end of member 43 and at its other end against the set screw 45 mounted in a lug 46'on the member 27, the tension of saw 32 being thus of a yieldable nature.

A cap nut 47 disposed on the lower end of the hub of each pulley constitutes a means for catching all grease dripping from the bearings.

The purpose of the areuate adjustability of the shafts 38, which are always in the vertical plane common to the axes thereof, is to adjust the pulleys 30 and 31 to the positions wherein the band-saw 32 will remain pro rly positioned on or engaged with said pul eys during its operation. The said pulleys are further so positioned relatively to the flanges 29 and the channeled portion 24 of the frame, so that the band-saw 32 is disposed with its bottom edge slightly above the lower edges of said flanges. At the points in'the flanges 29 disposed at the ends of the gap between the members 26 and 27- in which the band-saw is exposed, there are slots for the passage of said saw, there being which is automatically applied as soon as the circuit through the motor 3 is opened. It comprises the electro-magnet 53 rigid with the member 26 and interposed in the motor circuit. Associated therewith is the armature 54 constituting a part of the arcuate brake-shoe 55. This is spring-held in normal contact with the face of pulley by means of the spring 56 abutting at one end against a lug 57 of member 26. At its ends the brake-shoe is pivotally connected with a pair of toggle links 58 extending at an angle to oppose the direction of rotation of the pulley 30. -At their other ends the said links are pivotally connected with collars 59 at the inner ends of reciprocable plungers 60 slidably mounted in bearings 61 integral with the member 26. Springs 62 are interposed between said bearings and said collars to normally hold the latter and the links 58 in position so that no pressure is exerted on the shoe 55 other than that exerted by spring .56. Obviously, when the shoe is thrown by the latter in contact with pulley 30 during rotation of the latter, the momentum of said pulley will cause the shoe 55 to be moved and will thereby change the angle of extension of the links 58 relatively to plungers 60 and thus move the latter against the action of springs 62 whose pressure is thus added to that of spring 56, the combined pressures thus applied to the shoe 55 being suflicient to stop the rotation of pulley 30 almost instant- 1y after opening the motor circuit. This stop action is followed by a slight reverse rotation of the pulley to return the shoe 55 to normal position so that upon closure of the motor circuit, it will be released from engagement with said pulley against the action of spring 56.

A handle 63 is mounted on the member 27 so that the frame may be lowered against the action of the sprin 25.

The toothed end of sleeve 14 cooperates with the toothed end of collar 17 to permit the frame24 to be disposed at any desired angle, itbeing sometimes necessary or de sirableto cut bone at angles to the normal vertical plane. The member 17 may be digitally moved against the action of spring 18 for disengagement of its teeth from those of said sleeve, and released for re-engagement upon completing the adjustment of the position of the frame 24.

The operation of the device will probably be readily understood from the foregoing description with further review.

It will be noted that the bearings at the lower ends of the stud-shafts carrying pulleys and 31 are disposed substantially in the plane of the faces of said pulleys over which the band-saw is trained so that said bearings are subjected to practically the whole strain or load while the bearings at the upper ends of said stud-shafts carry but little of said load. The lower bearings are, therefore, equipped with long anti-friction rollers and are not easily worn. The studshafts are preferably quite large in diameter to enable them to long withstand the leverage and vibration to which they are subjected.

In Fig. 13, I have shown a possible modification to eliminate the use of a flexible shaft and the sprocket gearing shown in Fig. 6. In the modified structure either or both of the end members 26 and 27 of the saw carrying frame 24 may be equipped with a field magnet 65 of a motor, the armature 66 of which is carried by the hub of the pulley 30 or 31.

It will be understood, of course, that l have illustrated and described the details of construction of the machine as shown without limitation to such changes therein as mechanical skill may dictate to overcome any defects that may develop in the practical operation of the machine. I

I claim as my invention:

1. A portable cutter comprising a supporting member vertically ad ustable in height and equipped in its lower end with a motor rigidly connected therewith, a saw-carrying frame pivotally connected with the upper end of said member, a band-saw operatively mounted in said frame, a flexible shaft operatively connecting said motor with said band-saw, and a telescopic device interposed between the motor shaft and the flexible shaft for permitting adjustment in height of the supporting member without interfering with the operative association of said flexible shaft with the motor shaft and the bandsaw.

2. A portable cutter comprising a supporting member vertically adjustable in height and equipped with a motor having a vertical shaft, a flexible shaft having a sleeve at its lower end telescopically associated with said motor shaft for maintaining the said shafts engaged as said supporting member is adjusted, a bearing on the upper end of said supporting member, an L-shaped shaft journalled at one end portion in said bearing, coacting means on said end portion and said bearing for preventing rotation of said shaft in said bearing, a saw-carrying frame having a bearing rece1v1ng the other end portion of said shaft, springs operatively associated with the latter and said frame for normally yieldably supporting said frame,

and a band-saw operatively carried by the latter and geared to said flexible shaft.

3. A portable cutter comprising a supporting member vertically adjustable in height and equipped with a motor having a cluding digitally operable means for adjust ing the position of said shaft in said bearing to vary the angle of projection of the other end portion of said shaft, a saw-carrying frame having a'bearing receiving the other end portion of said shaft, springs operatively associated with the latter and said frame for normally yieldably supporting said frame, and a band-saw operatively carried by the latter and geared to said flexible shaft.

4. A device of the kind specified including a saw-carrying frame having two substantially cylindrical shallow end portions and an intermediate straight channeled portion, all open at the bottom, a carrier for a studshaft mounted on the top of each of said end portions, said carriers arcuately adjustable on axes perpendicular to the axes of said shafts and parallel with eachother, said axes of adjustment being also perpendicular to a plane common to the axes of both said shafts, pulleys rotatably mounted on said shafts, a band-saw trained over said pulleys, and gearing between one of said pulleys and a source of power.

5. A device of the kind specified including a saw-carrying frame having two substantially cylindrical shallow end portions and an intermediate straight channeled portion, all open at the bottom, a carrier for a stud shaft. mounted' on the top of each of said end portions, said carriers arcuately adjustable on axes perpendicular to the axes of said shafts and parallel with each other, said axes of adjustment being also perpendicular to a plane common to the axes of both said shafts, a member slidably engaged with one end portion of said member in a direction parallel with said plane and carrying one of said arcuately adjustable carriers, a set screw associated with said slidable member, a compression spring interposed between the latter and said set screw, pulleys rotatably mounted on said shafts, abandintermediate straight channeled saw trained over said pulleys, said set screw and spring adapted to adjust the tension of said band saw, and gearing between one of one of said pulleys and a source of power.

6. A device of the kind specified includmg a saw-carrying frame having two substantially cylindrical shallow end portlons and an ortion, all open at the bottom, a carrier 'or a studshaft mounted on the top of each of sa1d end portions, said carriers arcuately ad ustable onaxes perpendicular to the axes of said shafts and parallel with each other, said axes of adjustment being also perpendicular to a plane common to the axes of both said shafts, pulleys rotatabl mounted on said shafts, a band-saw traine over said pulleys and adapted to travel through said channeled portion and providing an exposed portion spanning the open space between said end portions opposite to said channeled portion, an adjustable guide for said 1astnamed portion of said saw mounted on one of said end portions, and gearing between one of said pulleys and a source of power.

7. A portable cutter comprising a supporting member vertically adjustable in height and equipped with a motor having a vertical shaft, a flexible shaft having a sleeveat its lower end telescopically associated with said motor shaft for maintaining the said shafts en aged as said supporting memher is adjuste a bearing on the upper end of said supporting member, an L-shaped shaft journalled at one end portion in said bearing, coacting means on said end portion and said bearing for preventing rotation of said shaft in said bearing and including teeth at one end of said bearing, a companion toothed member non-rotatably and slidably mounted on said end-portion of said shaft, a compression spring for maintainin 1 said toothed member normally engaged with the toothed end of said bearing, a saw-carrying frame having a bearing, receiving the other end portion of said shaft, springs operatively associated with the latter and said frame for normally yieldably supporting said frame, and a band-saw operatively carried by the latter and geared to said flexible shaft.

8. In a machine of the kind specified, a band-saw, a pair of pulleys over which the same is trained, stud-shafts on which said pulleys are rotatably mounted, antifriction bearings interposed between the respective end portions of each of said hubs and its stud-shaft, one of said bearings disposed in alignment with the face of the pulley over which the band-saw is trained, and means associated with said stud-shaft and the frame for permitting arcuate adjustment of said shafts in a plane parallel with the portions of the band-saw spanning the space between the pulleys.

WILLIAM F. WELLS. 

